Expression of vascular endothelial growth factor (VEGF) in vulvar squamous cancer and VIN

Angiogenesis plays an important role both in progression of solid tumors and in metastasizing. An invasive growth of a neoplasm is mainly connected with appearing of blood vessels within a tumor. Inhibition of angiogenesis in solid neoplasms may deter both tumor growth and metastases. New treatment strategies based on suppressing of angiogenesis and selective damaging of neoplastic blood vessels may prove to be as efficient as those based on direct destruction of neoplastic cells. One of important angiogenic factors is vascular endothelial growth factor (VEGF), which is produced by neoplastic cells and shows high promitotic activity almost entirely for endothelial cells (paracrine activity). We decided to investigate VEGF expression in precancerous lesions as well as in squamous cancers of vulva. Our material included 31 cases of vulvar squamous cancer, 28 cases of VIN (vulvar intraepithelial neoplasia) III, 10 VIN II cases and 12 VIN I cases. A diagnosis was established according to WHO criteria on the ground of post-operative histopathological examination complemented with proliferation index estimated by the use of MIB-1 antibody. Immunohistochemical examinations were performed on paraffin-embedded material, using MIB-1 antibody (Immunotech), VEGF antibody (Santa Cruz), Goat serum Normal (DAKO), DAKO StreptAB-Complex/HRP Duet, Mouse/Rabbit DAKO DAB Chromogen Tablets, TBS (Sigma). Positive cytoplasmic expression of anti-VEGF polyclonal antibody (diffuse and/or focal and of various intensity) was observed in almost all samples from precancerous and cancerous lesions. The expression was especially strong and diffuse in all cancer cases; in cases of VIN it was mainly focal and weak.